摘要
为了分析CaCO_3对煤热解特性的影响,以脱灰后的神木煤为研究对象,采用管式炉热解装置,在500～800℃范围内,对添加CaCO_3质量分数分别为0%,2%,5%,10%的煤样的热解产物产率和气体成分组成进行了实验研究。结果表明：CaCO_3会与煤中的羧基发生反应,Ca作为大分子基团的交联点,会固定一部分大分子碎片,从而明显增加半焦产率并降低焦油产率,同时,CaCO_3还会明显改变热解气体成分,并且在低温区和高温区影响不同。在500～600℃时,CaCO_3会促进CH4,CO_2和轻质烃类气体C_2-C_3的析出,但对CO基本无影响;在700～800℃时,CaCO_3分解产生的CaO_对H_2,CH_4和轻质烃类气体C2-C3的产率的促进作用与CO_2对它们的抑制作用相互竞争,CO_2浓度升高促进了半焦气化反应,会明显增加CO的产率。
Taking the demineralized Shenmu coal as samples,the influence of calcium carbonate on pyrolysis characteristic of coal was experimentally investigated on a tube furnace reactor.The pyrolysis product yields and gas component of coal samples with different amounts（0%,2%,5%,10%）of calcium carbonate were obtained,within the temperature range from 500℃to 800℃.The results show that,the calcium carbonate will react with the carboxyl in the coal,as the crossliking point,Ca will fix a few large molecule fragments,thus to increase the semi-coke yield and reduce the tar yield.At the same time,the calcium carbonate will change the pyrolysis gas components dramatically,and the influence is different at low temperatures from high temperatures.At temperature ranging from 500℃to 600℃,the calcium carbonate will enhance the precipitation of CH_4,CO_2 and light hydrocarbon gas C_2-C_3,while it has little effect on the CO production.At temperature ranging from 700℃to 800℃,the calcium carbonate decomposes and generates CaO and CO_2,the CaO promotes the production of H_2,CH_4 and light hydrocarbon gas C2-C3,while CO_2 has an inhibition effect on this process.As a result,the yields of H_2,CH_4 and light hydrocarbon gas C2-C3 nearly have no change.However,the excess CO_2 can promote the semi-coke＇s gasification,which sharply increase the CO yield.
出处
《热力发电》
CAS
北大核心
2016年第1期14-19,共6页
Thermal Power Generation
基金
国家自然科学基金项目(51276160)
关键词
煤
热解
管式炉
碳酸钙
半焦
焦油
气化反应
coal
pyrolysis
tube furnace
calcium carbonate
semi-coke
tar
gasification
